3-DIMENSIONAL CONFORMAL RADIOTHERAPY IN BRONCHOGENIC-CARCINOMA - CONSIDERATIONS FOR IMPLEMENTATION

Lung cancer continues to be a major health problem worldwide. In spite of significant technological and scientific medical progress, the final outcome of this disease is still dismal. Except for a small percentage of patients with early stage who undergo complete surgical resection, local control continues to be disappointingly low. In a recent report by Arriagada et al. (Arriagada R, Le Chevalier T, Quoix E, Rufie P, de Cremoux H, Douillard J-Y, Tarayre M, Pignon, J-P, LaPlanche, A. Effect of chemotherapy on locally advanced non-small cell lung carcinoma: a randomized study of 353 patients. Int J Radiat OncoI Biol Phys 1991; 20: 1183-1190), biopsy proven local control by RT alone was only 17%. This team also found that the addition of combination chemotherapy, although it has decreased distant metastasis, has not had any impact on local control. There are some indications in the literature to suggest that higher doses of radiation to the target volume (tumor) may result in improved local control in inoperable non-small cell lung cancer. This temptation for increasing dose to target volume, however, should not result in inappropriate normal tissue side-effects and complications. Three-dimensional (3D) conformal radiation therapy has shown a significant potential for improving radiation treatment planning in several sites, both for tumor coverage and sparing normal tissue. Using this technology, progress in uncomplicated locoregional control of lung cancer may become a reality. The following is a review of literature and analysis of the currently available information on this subject.